%I A158227
%S A158227 224,449,674,899,1124,1349,1574,1799,2024,2249,2474,2699,2924,3149,3374,
%T A158227 3599,3824,4049,4274,4499,4724,4949,5174,5399,5624,5849,6074,6299,6524,
%U A158227 6749,6974,7199,7424,7649,7874,8099,8324,8549,8774,8999,9224,9449,9674
%N A158227 a(n)=225*n-1 (n>0)
%C A158227 If A=[A158226] 225*n.^2-2*n (n>0g 223, 896, 2019, , ,.,); Y=[A010854] 
               15 (15, 15, 15,.,); X=[A158227] 225*n-1 (n>0, 224, 449, 674, , .,
               ), we have, for all terms, Pell's equation X^2-A*Y^2=1. Example: 
               224^2-223*15^2=1; 449^2-896*15^2=1; 674^2-2019*15^2=1.
%H A158227 Edward Everett Withford, <a href="http://quod.lib.umich.edu/cgi/t/text/
               text-idx?c=umhistmath;cc=umhistmath;idno=abv2773.0001.001;view=toc">
               Pell Equation</a>
%H A158227 Wolfram MathWorld, <a href="http://mathworld.wolfram.com/PellEquation.html">
               Pell Equation</a>
%H A158227 Vincenzo Librandi, <a href="http://mathforum.org/kb/message.jspa?messageID=5785989&tstart=0">
               X^2-AY^2=1</a>
%F A158227 a(n)=225*n-1 (n>0)
%e A158227 For n=1, a(1)=224; n=2, a(2)=449; n=3, a(3)=674
%Y A158227 Cf. A010854, A158226
%Y A158227 Sequence in context: A050241 A046296 A094209 this_sequence A061524 A156813 
               A146745
%Y A158227 Adjacent sequences: A158224 A158225 A158226 this_sequence A158228 A158229 
               A158230
%K A158227 nonn
%O A158227 1,1
%A A158227 Vincenzo Librandi (vincenzo.librandi(AT)tin.it), Mar 14 2009